Manufacture of motor fuel



Juiy 7, 1936. E. w. lsoM MANUFACTURE OF MOTOR FUEL Filed May l, 1930INVENTOR /Sam @am w QM BY f./Q.

ATTORNEYS lPatented July 7, 1936 MANUFACTURE OF MOTOR FUEL Edward W.Isom, Scarsdale, N. Y., assignor to Sinclair Benning Company, New York,N. Y., a

corporation of Maine Application May 1, 1930, Serial No. 448,929v

3Claims.

This invention relates to improvements in the manufacture of motor fuelgasoline. The invention has several advantages and includes improvementsimportant in several respects.

5` The invention provides -for the production of motor fuel gasoline anddry, merchantable coke, or motor fuel gasoline, 'distillates of gas oilof kerosene character and dry, merchantable coke, as end products,without involving the production of residual fuel oil or low grade coke.

The invention is applicable generally to a wide range of stocks,including clean stocks and dirty stocks. It is applicable, for example,to kerosene, gas oil, relatively clean reduced crude oil,

relatively dirty reduced crude oil, residual fuel oil includingresiduals produced in cracking operations, tars, etc.

In one aspect, the invention provides for the conversion of residualfuel oil, produced in other operations, into more valuable products,motor fuel gasoline and dry, merchantable coke or motor fuel gasoline,distillates of gas oil of kerosene character and dry, merchantable coke.

The invention provides for an increase in the recoveryV of motor. fuelgasoline, or motor fuel gasoline and distillates of gas oil of kerosenecharacter, from higher boiling stocks, and particularly from dirtyhigher boiling stocks.

The invention provides for the production of motor fuel gasoline bysevere cracking opera-l tions producing anti-knock values of a highorder but improved with respect to stability.

The several advantages of the invention are,

moreover, secured in an operation of satisfactory economy.

In one aspect, the invention includes improvements in the processesdescribed in Letters Patent No. 1,757,843 issued to Sinclair RefiningCompany, May 6, 1930, on an application of Eugene C. Herthel and HarryL. Pelzer and in application Serial No. 340,996, filed February 18,1929,by Harry L. Pelzer.

The invention comprises the maintenance of free hydrogen `in an extremestate of dispersion in a high temperature region of active reactionthrough which the hot oil products of a severe cracking operation passwhile still at high temperature and through which pitch constituentspass as they are about to become coke. The free hydrogen may beintroduced as such, or it may be produced, or in part produced, withinthe region of reaction by the introduction of steam, under appropriateconditions.

The temperature of the region of reaction may be maintained by the heatof the hot oil products (Cl. 19E-58) of the severe cracking operationpassing therethrough. Additional heat may be supplied by superheatingthe hydrogen or hydrogen-containing gas, or steam, troduced into theregion of reaction. 5

The pressure in the region of reaction may vary from a pressureapproximating atmospheric pressure up to a pressure of several hundredpounds per square inch, for example, or more. However, one importantadvantage of the inven- 10 tion is that it does not necessitate themaintenance of high pressures but may be carried out under relativelylow pressure.

In carrying out the invention, hot oil products from a severe crackingoperation, the superheat- 15 ed hydrocarbon vapors and gases from avaporphase cracking operation, for example, are passed through a liquidbody of oil, being introduced into the liquid body of oil beneath itsliquid level and passed upwardly therethrough, the oil thus be- 20 ingreduced to coke, and free hydrogen, oi' a gas mixture rich in freehydrogen, is passed through the liquid body of oil together with the hotoil products from the severe cracking operation.

Steam may be passed ythrough the liquid body in 25 addition to thehydrogen or hydrogen-containing gas, -or under appropriate conditions,steam may be passed through the liquid-body of oil, and coke, with thehot oil products from the severe cracking operation instead of thehydrogen 30 or hydrogen-containing gas.

The coklng operation is carried out as described in Letters Patent No.1,757,843, mentioned above. In the coking operation, the initialformation of coke establishes a dispersion 35 means about the point ofintroduction of the hot oil products from the severe cracking operationpeculiarly effective in accomplishing dis-- persion to an extreme degreeof the superheated gases and vapors entering the overlying oil and 40pitch, through the coke formed. As pitch. is formed in the oil body, inexcess of that soluble in thevoil, it precipitates as a nlm overlyingthe accumulating coke and undergoing conversion to coke. v 45 Followingthe initial formation of coke, gas introduced through the coke issimilarly subject to extreme dispersion in the oil and pitch overlyingthe accumulating coke, whether introduced at the point of introductionof the hot oil prod- 50 ucts from the severe cracking operation or, intothe coke, at some other point.

The region including the film of pitch overlying the accumulating cokeand theadjacent coke and oil is the region of active reaction 55 Acarrying out the invention.

to which reference has been made. Within this region, the oil and pitchconstituents present are, at the prevailing high temperature, normallyreactive and the gases and vapors passing through this region are, atthe prevailing high temperature and because of the extreme dispersion towhich they are subjected, super-normally reactive.

In one aspect, the super-[normally reactive condition of the vapors andgases within the region of reaction eiected by extreme dispersion of thevapors and gases in carrying out the invention, makes it possible tomaintain satisfactory reaction rates under relatively low pressures; inanother aspect, it makes it possible to maintain high reaction ratesunderhigh pressures.

Where the accumulating coke is maintained at a temperature upwards of1200 F. or thereabout, steam may be introduced into the regionofgreaction, instead of hydrogen or a hydrogencontaining gas. Within thetemperature range of the water gas reaction, steam introduced into theregion or reaction will react with the coke to form free hydrogen andcarbon monoxide, hydrogen so formed being in effect introduced into theregion of reaction in a nascent state.

While the invention involves the production of coke as an end product,the coke produced is a valuable, dry, merchantable coke and theproportion of coke produced with respect to the oil treated is small andmay be made very small.

In the region of reaction, the more reactive constituents of the motorfuel gasoline component of the hot oil products discharged from thesevere cracking operation, producing instability in the motor fuelproduct, are subjected to conditions convertingsuch constituents intoless reactive and more stable constituents of the motor fuel product orof the gas oil of kerosene character distillate products and into pitchin turn converted into coke. Because of the high temperature prevailingin the region of reaction, the resulting motor fuel gasoline product,although of improved stability, retains in large measure the anti-knockvalues produced in the severe cracking operation. The motor fuelgasoline product of the invention is thus t0 be distinguished fromgasoline products produced, for example, by simple hydrogenation of agasoline produced by a severe cracking operation.

The invention win be further described in com' nection with theaccompanying drawing, which illustrates, diagrammatically andconventionally, in elevation and partly in section and with parts brokenaway, one form of apparatus adapted for It will be understood that theinvention may be carried out in other and in different forms ofapparatus; the particular apparatus illustrated in the accompanyingdrawing is illustrated merely for purposes of exemplication.

The apparatus illustrated comprises a coking receptacle I, within whichthe region of active,

reaction of the invention is maintained during operation, a crackingheater 2, a superheater 3, a scrubbing tower 4, fractionating towers 5and 6, a condenser 'l and a receiver 8. The cracking heater 2 and thesuperheater 3 are arranged to discharge into the lower end of the cokingreceptacle I through connection 9. Vapors and gases escaping from theupper part of the coking receptacle I are discharged, in normaloperation, into and beneath the liquid level of a liquid body of oilmaintained in the lower 'end of the scrubbing tower 4 throughconnections |0 and The oil mixture constituting the liquid bodymaintained in the lower part of the scrubbing tower 4 is forced into theupper part of the coking receptacle through connections |2 and I3 bymeans of pump |4. Vapors and gases escaping from the upper part of thescrubbing tower 4 are discharged into the lower part of thefractionating tower 5 through connection I5. The oil mixture collectingin the lower part of the fractionating tower 5 is supplied to thecracking heater 2 through connections I6 and I1 by means of pump 8.Vapors and gases escaping from the upper part of the fractionating tower5 are discharged either into the lower 1 part of the fractionating tower6 through connections I9 and 2|), or directly to the condenser 'Ithrough connections I9, 2| and 22. Vapors and gases escaping from theupper part of fractionating tower 6 are discharged to the condenser 'Ithrough connection 22. Condensate is discharged from the receiver 8.through connection 23, uncondensed vapors and gases being dischargedtherefrom through connection 24. Each of the towers 4, 5 and 6 isillustrated as provided, 25

ture, for example, may be supplied through con- 3 nection |I and heatedto a temperature, as discharged through connection 3I, approximatingD-1200" F. under a pressure, as discharged through connection 3|,approximating 10-20 pounds per square inch (above atmospheric pressure).Such a vapor-phase cracking operation may be carried out, for example,as described in application, Serial No. 198,621, filed June 13, 1927, byHarry L. Pelzer, and the hot oil products therefrom discharged throughconnections 3| 4 and 9, or the digesting drums may be omitted, as

in the apparatus illustrated in the accompanying drawing. Or a gas oil0r kerosene character stock or stock mixture, for example, may be heatedto a temperature, as discharged through con- I The scrubbing tower 4 andthe fractionating 5' towers 5 and 6 may be operated, for example, as

described in application Serial No. 345,199, led March 7, 1929, byEugene C. Herthel. A liquid body of oil, from which liquid oil issupplied to the coking receptacle and to which raw oil and entrainedconstituents scrubbed from the vapors and gases escaping from the cokingreceptacle are supplied is maintained in the lower part oi the scrubbingtower 4 and the vapors and gases escaping from the coking receptacle Iare discharged into and beneath the liquid level of this liquid body ofoil through connection I. Raw oil, particularly relatively dirty rawoil, reduced crude oil for example, may be supplied to the scrubbingtower 4 at an intermediate point,

throughI connection 32, or better, directly to the liquid body of oil inthe lower part of the scrubbing tower 4, through connection 33. Raw oil,

particularly relatively clean raw oil, a gas oil or 7 15 mixed raw 45permit the general operation to be 60 tures of hydrogen and hydrocarbongases,

65 reintroduced 70 thermal decomposition.

75 gen-containing gas or .towerlasaremningmediumthrwghconnection .1 Theoperation of the scrubbing tower l may be controlled, or vcontroleffected by raw oil supplied through connection 32 or connec- Vtion 3lor both of these connections maybe supplemented `byregulated circulationof a cooling medium through the reflux condenser 2i.v Where both ofthefractionating towers 5- andiareuseiarelativelyhigherboilingfrac@ tionis separated in the tower I and a relatively lower boiling fraction inthe tower l. Either or both of these fractions, together with any adoilintroduced into the fractionating towers 5 or O or either of them, maybe supplied tothecrackingheaterl. The operationofthe fractionatingtowers i and 6 maybe controlled by the regulated introduction of rawoil, bestv 20 relatively clean raw oil,`a ,gas oil or kerosene characterstock for example, through connections 35 and 3i or byregulated'circulation of a cooling medium through the reflux -condensers20 and 21, or by both of these means conjointly.

The vapors and gases escaping to the condenser 1 through connection 22may be subjected to .direct renning treatment on their way= to thecondenser. For example, this gas-vapor mixture may be subjected todirect refining treatment 30 as describedin application Serial No.257,958,

led February 29, 1928, by Eugene C. Herthel.

The coking receptacle I is, with advantage,

yarranged andoperated with respect to the scrubbing tower 4 as describedin application Serial 35 No. 340,996, led February 18, 1929, by Harry L.Pelzer. The coking receptacle I may, with advantage, be arranged asdescribed in application, Serial No. 344,952, filed March 7,1929, byOliver F. Campbell and Eugene C. Herthel for the purpose of dischargingvaccumulated charges of coke. Since individual coking receptacles mustbe operated intermittently to permit the d ischarge of accumulatedcharges of coke, a plurality of coking receptacles may be provided to edout continuously. Such a group of coking receptacles may, withadvantage, be operated as described in application Serial No. 19, 1929,by Harry L. Pelzer.

In carrying out the invention in the apparatus illustrated, the gas andvapor mixture introduced into the lower end of the coking receptacle lthrough connection l includes, in addition to thel hot oil productsdischarged from the cracking or steam or a mixture of two or more ofthese gases supplied either through connection 31 or through connection38 or through both of these connections. Suitable gas mixtures includemixproduced, for example,` by thermal decomposition of hydrocarbon gasmixtures. The gas mixture escaping through connection 24, for example,in-

cluding any remaining free hydrogen, may be into the lower end of thecoking receptacle I through connection 9 and the free hydrogen contentof the reintroduced gases may rst be increased by the addition oi.' freehydrogen or by the subjection of the gas mixture to Such thermaldecomposition of hydrocarbon gases may be effected, for example, bypmngthe gases through checkerwork or coke maintained at a temperatureupwards of 1200-1400" F. '111e hydrogen or hydrosteam introduced intothe 341,214, med February lower end-of the coking receptacle I issuperheated.- if necessary, to a temperature sumcient to maintain therequisite temperature within the region ofreaction in the cokingreceptacle. The apparatus illustrated includes a superheating furnace 3for this purpose. Steam may be superheated in the heating coil 39 andhydrogen or a hydrogen-containing gas may be superheated in the heatingcoil I0. It will be understood that a separate super-heating furnace maybe provided 10 for superheating steam and the hydrogen orhydrogen-containing gas separately or that only the steam or only thehydrogen or hydrogen-containing gas may be superheated. f

In carryingv out the invention in the apparatus illustrated, a mixtureof the hot oil products discharged from the cracking furnace 2 andhydrogen or hydrogen-containing gas is introduced into t lower end ofthe coking receptacle I, at a perature as introduced approximating 1150-1 00 F. for example, through a Ibody of coke, formed about the inletfrom the connection 9 as the operation 'of the coking receptacle isinitiated, into a fluid body of oil' and pitch overlying theaccumulating' coke and from which pitch is pre- 25 clpitating upon theaccumulating coke, undergoing as precipitated conversion to coke. As theintroducedvmixture of vapors and gases passes through the accumulatingcoke, it is subdivided to enter the overlying oil and pitch an extremedegree therethrough. This extreme dispersion enormously increases thearea of contact between the vapors and gases, and the oil and pitch,particularly within the region imidispersed to mediately adjacent to the-upper level of the accumulating coke, thus promoting` heat transferbetween the vargrs and gases and the oil and pitch and affor ng themaximum opportunity for the attainment of the equilibrium represented bythe concentration of free hydrogen within this region. The concentrationof free hydrogen with respect to the oil and pitch within this -regionmay be increased by increasing the pressure prevailing in the cokingreceptacle. The coking receptacle [may be operated, for example, under apressure approximating 0-10 pounds per square inch or under a pressureapproximating 90-150 pounds per square inch or under a pressureapproximating 3D0-350 pounds per square inch or under higher pressures.The temperature of the vapors and gases escaping from the upper part ofthe coking receptacle I may be maintained, for example, in theneighborhood of 1050-1250" F. and may advantageously be increasedsomewhat as coke accumulates withinthe coking receptacle.

Thejnvention will be further exemplied by the following examples ofoperations embodying the invention as carried out in the apparatusillustrated: l

An oil mixture comprising reduced crude oil, having a gravity of aboutl5 A. P. I., is supplied to the coking receptacle l through connectionI3 at a rate of about Z50-450 gallons Vper hour and 65 at a temperatureapproximating '15o-800 F. A

gen preheated to a temperature sufficient to bring pressure distillationcracking operations, having a gravity of about A. P. I., is supplied tothe coking receptacle I through connection I3 at al rate of about350-500 gallons per hour and at a temperature approximating 'Z50-800 F,A gas oil character stock, having a gravity of about 35 A. P. I.,\ issupplied to the cracking heater 2 through connection I'I at a rate ofabout 1000- 1500 gallons vper hour and heated therein to a temperature,as discharged through connection 3 I,

approximating 1160-1180 F. under a pressure, as discharged throughconnection 3 I, approximating 20 pounds per square inch. A hydrocarbongas mixture including about 35% free hydrogen preheated to a temperaturesuiicient to bring the temperature of the resulting mixture passingthrough connection 9 to about 1200-1300 F., is supplied throughconnection 38 at a rate of about 50,000-100,000 cubic feet per hour. Thecoking receptacle I is maintained under a pressure approximating 3-5pounds per square inch.

An oil mixture comprising reduced crude oil, having a gravity of about15 A. P. I., is supplied to the coking receptacle I through connectionI3 at a rate of about 200-300 gallons per hour and at a temperatureapproximating 750-800 F. A kerosene character stock, having a gravity ofabout 40 A. P. I., is supplied to the cracking heater 2 throughconnection I'I at a rate of about 1000- 1200 gallons per hour and heatedtherein to a temperature, as discharged through connection 3I,approximating 1175-1200 F. under a pressure, as discharged throughconnection 3|, approximating 20D-250 pounds per square inch; Freehydrogen preheated to a temperature suilcient to bring the temperatureof the resulting mixture passing through connection 9 t0 about 1200-300F. is supplied through connection 38 at a rate of about 40,000-65,000cubic feet per hour. The coking receptacle I is maintained under apressure approximating 3-5 pounds per square inch.

An oil mixture comprising reduced crude oil, having a gravity of about15 A. P. I., is supplied to the coking receptacle I through connectionI3 at a rate of about 20D-300 gallons per hour and at a temperatureapproximating 'Z50-800 F. A gas oil character stock having .a gravity ofabout 35 A. P. I. is supplied to the cracking heater 2 throughconnection I1 at a rate of about 900- 1200 gallons per hour and heatedtherein to a temperature, as discharged through connection 3l,approximating 10501150 F. under a pressure, as discharged throughconnection 3|, approximating 400 pounds per square inch. A hydrocarbongas mixture including about 50% free hydrogen preheated to a temperaturesucient to bring the temperature of the resulting mixture passingthrough connection 9 to about 1200-1250 F. is supplied throughconnection 38 at a rate of about 40,00080,000 cubic feet per hour. Thecoking receptacle I is maintained under a pressure approximating -125pounds per square inch.

' An oil mixture comprising reduced crude oi1,

having a gravity of about 15 A. P. I., is supplied to the cokingreceptacle I through connection I3 at arate of about 3D0-400 gallons perhour and at a temperature approximating 'TSO-800 F. A kerosene characterstock, having a gravity of about 40 A. P. I., is supplied to thecracking heater 2 through connection I'I ata rate of about 1000-1200gallons per hour and heated therein 5 to a temperature, as dischargedthrough connection 3|, approximating 1175-1200 F. under a pressure, asdischarged through connection 3I, approximating 500-600 pounds persquare inch. Free hydrogen preheated to a temperature sufii- 10 cient tobring the temperature of the resulting mixture passing throughconnection 9 to about 1200-1300" F. is supplied through connection 38 ata rate of about 50,000-75,000 cubic feet per hour. The coking receptacleI is maintained 15 under a, pressure approximating 40G-500 pounds persquare inch.

An oil mixture comprising reduced crude oil,

having a gravity of Aabout 15 A. P. I. is supplied to the cokingreceptacle I through connection I3 at a rate of about 200-300 gallonsper hour at a. temperature approximating 750-800 F. A kerosene characterstock, having a gravity of about 40 A. P. I., is supplied to thecracking heater 2 through connection I'I at a rate of about 900-1000 25gallons per hour and heated therein to a temperature, as dischargedthrough connection 3|, approximating 11501200 F. under a pressure, asdischarged through connection 3l, approximating 20 pounds per squareinch. A gas mix- 30 ture including about 40% free hydrogen and 60% steampreheated to a temperature sufficient to bring the temperature of theresulting mixture passing through connection 9 to about 1200-1300* F. is-supplied through connections 31 and 38 at 35 a rate of about20,000-50,000 cubic feet per hour. The coking receptacle I is maintainedunder a pressure approximating 3-5 pounds per square inch.

An oil mixture comprising reduced crude oil, having a gravity of about15 A. P. I., is supplied to the coking receptacle I through connectionI3 at a rate ofabout 30D-500 gallons per hour and at a temperatureapproximating 750-800 F. A gas oil character stock, having a, gravity ofabout 35 A. P. I., is supplied to the cracking heater 2 throughconnection II at a rate of about 1000-1500 gallons per hour and heatedtherein to a temperature, as discharged through connection 3|,approximating 1160-1180 F., under a pressure, as discharged throughconnection 3|, approximating 20 pounds per square inch. A gas mixtureincluding about 30% of steam, 20% of free hydrogen and 50% ofhydrocarbons preheated to a temperature suiiicient to bring thetemperature of the resulting mixture passing through connection 9 toabout 1250-1300 F., is supplied through connections 31 and 38 at a rateof about 30,000-65,000 cubic feet per hour. The coking receptacle I ismaintained under a pressure ap- 60 proximating 3 5 pounds .per squareinch.

An oil mixture comprising reduced crude oil, having a gravity of about15 A. P. I., is supplied to the coking receptacle I through connectionI3 at a rate of about 250-450 gallons per hour and 65 heated to atemperature sufcient to bring the temperature of the resulting mixturepassing through connection 9 to about 1250-1300 F. is supplied throughconnection 31 at a rate of about 40,000-80,000 cubic feet per hour. Thecoking receptacle I is maintained under a pressure approximating 3-5pounds per square inch.

An oil mixture comprising reduced crude oil, having a gravity of about15 A. P. I., 'is supplied to the coking receptacle i through connectioni3 at a rate of about 200-300 gallons per hour and at a temperatureapproximating '750800 F. A kerosene character stock having a gravity ofabout 40 A. P. I., is supplied to the cracking heater 2 throughconnection l1 at a rate of about 1000-1500 gallons per hour and heatedtherein to a temperature, as discharged through connection 3l,approximating M75-1200 F. under a pressure, as discharged throughconnection 3l, approximating 200-250 pounds per square inch. Steampreheated to a temperature sufiicient to bring the temperature of theresulting mixture passing through connection 9 to about 1250l300 F. 1ssupplied through connection 38 at a rate of about 50,000-'75,000.cubicfeet per hour. The coking receptacle I is maintained under apressureapproximating -200 pounds per square inch.

The gas mixtures containing free hydrogen more particularly useful incarrying out' the invention are those containing upwards of 20% or,better, upwards of 30% of free hydrogen. 1n

referring to. severe cracking operations, reference is intended tocracking operations in which oil is heated to a temperature high enough,generally upward of 950 F., to produce a motor fuel gasoline producthaving anti-knock values of a high order.

I claim:

1. In the manufacture of motor fuel gasoline, the improvement whichcomprises subjecting an oil to severe vapor phase cracking conditionsupwards of 950 F., thereby producing a mixture of vapors and gases,heating an additional gas mixture containing-upwards of about 20% offree hydrogen to a temperature upwards of 1200 F., simultaneouslypassing the highly heated vapors and gases from the vapor phase crackingoperation together with the additional highly heated hydrogen-containinggas mixture upwards through an accumulating body of coke into anoverlying body of oil and pitch undergoing conversion to coke. V

2. In the manufacture of motorfuel gasoline, the improvement whichcomprises subjecting an oil 'to severe vapor phase cracking conditionsupwards of 950F., thereby producing a mixture of vapors and gases,heating an additional gas mixture containing upwards of about 20% offree hydrogen to a temperature upwards of 1200 F., simultaneouslypassing the highly heated vapors and gases from the vapor phase crackingoperation together with the additional highly heated hydrogen-containinggas mixture upwards through an accumulating body of coke into anoverlying body of oil and pitch undergoing conversion to coke at atemperature upwards of 1200 F.

3. In the manufacture of motor fuel gasoline, the improvement whichcomprises subjecting an oil to severe vapor phase cracking conditionsupwards of 950 F., thereby producing a mixture .of vapors and gases,superheating steam to a temperature substantially in excess of 1200 F.,uniting the superheated steam and the vapors and'gases from the vaporphase cracking operation,l introducing the mixture at a temperature inexcess of 1200 F. upwardly into a coking zone adapted to receive anaccumulating charge of coke, and passing the mixture of superheatedsteam and the hot products from the vapor phase cracking operationupwardly through a body of coke accumulating in said coking zone a ndinto an overlying body of oil and pitch undergoing conversion to coke ata temperature upwards of 1200 F.

EDWARD W. ISOM.

